I have been to 3 current MLB stadiums. Oriole Park @ Camden Yards, Nationals Park, and Petco Park (San Diego Padres). I have also been to Memorial Stadium (Orioles) and RFK (Nationals).
I guess that Oriole Park is my favorite so far. The first retro Park that spawned the new stadium growth. This stadium has the retro look, the out of town scoreboard in the right field wall, the bullpen in left center, the angled outfield walls with ads on them, and the gold plaques up on Eutaw Street where home runs land, + the warehouse.
Only 1 player has hit the warehouse with a home run and that was Ken Griffey Jr. at the 1993 Home Run Derby. So technically no one has hit it in a game.